Abstract:

Big cities in California are notorious for traffic congestion, which is widely viewed to be detrimental to both the regional economy and quality of life. Both metropolitan Los Angeles and the San Francisco Bay Area regularly rank at or near the top of lists ranking the nation’s most congested areas. The case that Californians and their regional economies are hurt by traffic congestion seems obvious. But is it?

Professor Brian Taylor from the UCLA Institute of Transportation Studies explores this question by considering the role of transportation in, and the effect of traffic delays on, activity participation, accessibility, and the regional economies in LA and the Bay Area. He will report on research with colleagues at UCLA and the University of Virginia on how travel speeds and differences in the built environment within and across communities interact to determine trip-making and access to jobs across a variety of economic sectors. Access refers to the ability of people and firms to avail themselves of economic and social opportunities in space, which is a function not only of the speed at which one is able to travel, but also of the proximity of desired destinations both within and across communities.

So what are the costs of traffic delays to the life and economies of California’s cities? In a nutshell, Taylor and his colleagues find that most of the functions of everyday life – travelling to and from school and work, delivering goods, attending meetings, and shopping for groceries – are shaped more by “access” to destinations than by simple measures of either mobility or traffic delay. Put simply, jobs, friends, medical care, farmers’ markets, and more tend to be more easily and more frequently accessed via the congested streets and roads of communities like Palo Alto, San Francisco, Santa Monica, and West Hollywood, than via the free-flowing streets and roads in outlying areas. This conundrum – that access and activities are often greatest where traffic is heaviest – is at the key to understanding the highly variable effects of traffic congestion across metropolitan areas.